An enhanced vision system (EVS) for an aircraft is designed to enhance pilot situational awareness during flight at night or during poor weather conditions by providing a sensor enhanced view of the outside environment. The imagery may be displayed conformally on a combiner of a Head-up Guidance System, increasing both safety and operational capability of the aircraft.
Enhanced vision systems for aircraft utilize relatively high cost imaging sensors mounted to the body of the aircraft. The imaging sensors may include infrared sensors, thermal imagers, etc. configured to recognize image input data, such as incandescent light sources. However, thermal imagers are not configured to differentiate colors associated with the source of the incandescent light. These colors may be critical to a correct interpretation of an aircraft scene (e.g. VASI or PAPI lighting, rabbit-lights, end lights, center lights, edge lights, taxiway lights). Further, thermal imagers are not configured to recognize “cold” sources of light, such as reduced energy consumption light emitting diode (LED) or fluorescent lights sources that are increasingly being used at many airfields.
The performance of enhanced vision system sensors often differs greatly dependent on the current weather conditions. In particular, sensor performance may degrade during certain weather conditions such as high density fog and large rain drops. Performance degradation can be caused by increased signal scattering, dominant absorption, weak propagation, etc.
Accordingly, there is a need for an improved system and method of providing an enhanced vision system in an aircraft. Further, there is a need for such a system configured to recognize and adjust imaging sensor selections based on current weather conditions. Yet further, there is a need for such a system and method coupled to a head up guidance system to provide an enhanced conformal image. Yet further, there is a need for such a system and method configured to modify the conformal image based on detected weather conditions.
It would be desirable to provide a system and/or method that provides one or more of these or other advantageous features. Other features and advantages will be made apparent from the present specification. The teachings disclosed extend to those embodiments which fall within the scope of the appended claims, regardless of whether they accomplish one or more of the aforementioned needs.